I am not sure that libutempter0 is the real culprit, however I find a very strange behavior:
If I preload libutempter mosh-server didn't crashes. Instead if I run mosh-server alone, it crashes: $ ldd /usr/bin/mosh-server linux-vdso.so.1 (0x00007ffce553b000) libtinfo.so.5 => /lib/x86_64-linux-gnu/libtinfo.so.5 (0x00007f8966678000) libprotobuf.so.9 => /usr/lib/x86_64-linux-gnu/libprotobuf.so.9 (0x00007f896634e000) libpthread.so.0 => /lib/x86_64-linux-gnu/libpthread.so.0 (0x00007f8966130000) libssl.so.1.0.2 => /usr/lib/x86_64-linux-gnu/libssl.so.1.0.2 (0x00007f8965ec7000) libcrypto.so.1.0.2 => /usr/lib/x86_64-linux-gnu/libcrypto.so.1.0.2 (0x00007f8965a64000) libutil.so.1 => /lib/x86_64-linux-gnu/libutil.so.1 (0x00007f8965860000) libz.so.1 => /lib/x86_64-linux-gnu/libz.so.1 (0x00007f8965645000) --> libutempter.so.0 => /usr/lib/x86_64-linux-gnu/libutempter.so.0 (0x00007f8965442000) libstdc++.so.6 => /usr/lib/x86_64-linux-gnu/libstdc++.so.6 (0x00007f89650be000) libm.so.6 => /lib/x86_64-linux-gnu/libm.so.6 (0x00007f8964dc0000) libgcc_s.so.1 => /lib/x86_64-linux-gnu/libgcc_s.so.1 (0x00007f8964baa000) libc.so.6 => /lib/x86_64-linux-gnu/libc.so.6 (0x00007f8964805000) /lib64/ld-linux-x86-64.so.2 (0x0000561792d06000) libdl.so.2 => /lib/x86_64-linux-gnu/libdl.so.2 (0x00007f8964601000) $ /usr/bin/mosh-server In dmesg I got "mosh-server[8320]: segfault at 0 ip...." Instead if I do $ LD_PRELOAD=/usr/lib/x86_64-linux-gnu/libutempter.so.0 /usr/bin/mosh-server mosh-server didn't crash... I am inclined to think that preloading the library I change the library arrangement in memory; this could hide/show some wrong memory access. Any idea how debug this ? G.Baroncelli